The use of some machines calls for supporting a workpiece while presenting it with a particular orientation to the machine. For example, consider the use of a common bending machine, known as a sheet bending brake, to bend a rectangular workpiece of sheet metal.
In order to bend such a workpiece using a typical sheet bending brake, like the brake described in U.S. Pat. No. 4,557,132, ordinarily the workpiece is first positioned upon the brake's clamping surface so that the edges of the workpiece have a desired orientation with respect to the brake. Commonly, a rectangular workpiece is positioned so that its front and rear edges are generally parallel with the front side of the brake.
Such a position allows the typical brake to bend the workpiece along a line that is generally parallel to the workpiece's front and rear edges. It is common for the human operator of a brake to position the workpiece manually, perhaps with the assistance of a helper, controlling the workpiece's orientation as it is presented to the brake. As the operator positions the workpiece upon the brake's clamping surface, he or she visually estimates, or perhaps determines with the assistance of temporary markings placed upon the workpiece, whether the workpiece is properly oriented or aligned relative to the brake.
Clearly, it would often be advantageous to equip a brake, or other machine, with an uncomplicated device to help support the workpiece and guide it to the proper orientation quickly, accurately and with relatively little effort, as the workpiece is positioned at the machine. It would also be advantageous if such a device could adjust easily and quickly to handle workpieces of varying size, since the dimensions of the workpiece presented to a brake or other machine may change from job to job.
Furthermore, it would also be advantageous if such a device could continue to support and control the orientation of the workpiece even if the rear edge of the workpiece must be raised above its original controlled position. Such a capability would, for example, permit the operator of a brake to place the front of a workpiece in a raised position (but with a controlled orientation) upon a clamping surface located somewhat higher than the device, and then to elevate and support the rear of the workpiece (while otherwise maintaining its orientation) so that the workpiece will be reasonably level when clamping occurs.
It would also be advantageous if such a device, once it has performed its function, could be collapsed to occupy relatively little space around the machine and to avoid any interference with the machine's operation. And it would be advantageous if such a device, even when so collapsed, could remain adjacent to the machine and therefore readily available for the device's next use.
Various devices that provide workpiece support have been described. For example, U.S. Pat. No. 5,379,816 teaches an auxiliary support device, suitable for use with table-type power tools, whose disclosed embodiment includes deployable legs and certain components that may slidingly extend to desired positions.
U.S. Pat. No. 4,410,023 teaches a work holder, suitable for use with a shearing or cutting machine, whose disclosed embodiment includes a horizontal support arm slidably disposed through brackets supported by upright members. That patent also discloses a modified adjustable extension member that includes a single extension arm that is hinged to the end of the horizontal support arm and is able to swing in a horizontal plane to broaden the area of support it provides. However, the swinging extension arm is not disclosed to support an edge guide to impart a preferred, predetermined orientation to the supported workpiece in the manner of the present invention.
U.S. Pat. No. 4,512,174 teaches a combined sheet bending brake and platform. The disclosed embodiment of the platform comprises a U-shaped tubular bar whose arms are telescopically received in the brake's rear rail, in a way that permits the platform to be extended outward, into a supporting position, from a storage position within the confines of the brake. The patent also describes a stop that can be moved along a track, for adjusting a sheet in proper position for bending. However, neither the disclosed platform nor the disclosed stop appears to provide adjustable workpiece support and orientation control in the same manner as the present invention.